The Suquamish Tribe is figuring out how to give tribal members more access to cockles by growing their own.
“We’re looking at different strategies for enhancing/restoring cockles on Suquamish beaches because there hasn’t been the same level of wild recruitment folks used to see,” said Elizabeth Unsell, a shellfish biologist for the tribe. “Tribal members want to go out and harvest cockles for their family.”
This year the tribe collected data on the growth and survival of cockles in experimental beach plots.
More than 1,000 cockles that started as wild recruited seed in geoduck tubes on a South Sound shellfish farm were planted on a tribal beach in May, then were measured and counted in July and August.
To test different protective strategies, cockles were planted in 36 plots of varying types. Each was 3 feet wide, some fully enclosed in large plastic rings the size of a small garden bed, some without the garden bed, some with mesh on top to protect them from predators and some without mesh. Control sites had no cockles added to them, so the tribe could look for wild recruitment, Unsell said.
The idea is to see what type of growing environment and outplanted cockle sizes are most successful when cockles are transferred from geoduck tubes.
Using cockles from different Puget Sound populations doesn’t pose a risk to wild cockle genetics, Unsell said. Testing has shown very little genetic variation from the north to south sound and out to Neah Bay, except for the populations in Hood Canal. Willapa Bay showed the most differentiation of all the sites tested. This opens the possibility of transferring cockle seed between different parts of Puget Sound to support restoration efforts.
Blood samples also were taken during data collection in July and August to test for bivalve transmissible neoplasia, or cockle cancer, at the Pacific Northwest Research Institute.Research has shown that cockle cancer can be transmitted like a virus.
South Sound is not known to have the cockle cancer in its shellfish, Unsell said, but the tribe and partners, including the Puget Sound Restoration Fund, want to know if these transferred cockles picked it up from the Suquamish beach this summer and if so, whether it’s seen at a higher rate than in the local population.
Preliminary results look promising, Unsell said, and work will continue next year.
Cockles collected from grow sites for measuring before being put back on the beach. Photo and story by Tiffany Royal
